Various processes have been proposed for the removal of nicotine from tobacco. Most of these processes, however, adversely affect the desirable flavor and aroma properties of the tobacco. Also, they are often complex and expensive to carry out.
U.S. Pat. No. 4,153,063 (Roselius) discloses a process for removing nicotine from tobacco in which tobacco is contacted with an extraction solvent in a supercritical state. It discloses both a single step extraction process and a multi-step extraction process. In the single step extraction process, moist tobacco is extracted with a solvent in a supercritical state. Because aroma components are also removed along with nicotine in this single step extraction process, the multi-step process is preferred. In the first step, dry tobacco is extracted with a solvent in the supercritical state to remove the aroma components. In the second step, the tobacco is moistened and again extracted with a solvent in the supercritical state to remove nicotine. The nicotine is separated from the solvent by either evaporating the solvent, contacting the solvent in a separate vessel with an acid, or adsorbing the nicotine on an active carbon column. In the third step, the stored aroma components from the first step are redissolved in a supercritical solvent and returned to the tobacco. This multi-step extraction process is expensive and time consuming. In addition, the prolonged handling of the aroma components may adversely affect their properties.